The Warbling Vireo
, Vireo gilvus
, is a
small North American songbird
breeding habitat is open deciduous and
mixed woods from Alaska to Mexico and the
nests along streams. It migrate to
Mexico and Central
Adults are 12 cm long and weigh 12 g. They are mainly
olive-grey on the head and upperparts with white underparts; they
have brown eyes and the front of the face is light. There is a
. They have thick
blue-grey legs and a stout bill. Western birds are generally
smaller and have darker grey crowns.
They forage for insects in trees, hopping along branches and
sometimes hovering. They also eat berries, especially before
migration and in winter quarters, where they are – like other
vireos – apparently quite fond of Gumbo-limbo
seeds, though they will not venture
into human-modified habitat to get them.
They make a deep cup nest suspended from a tree branch or shrub,
placed relatively high in the east and lower in the west. The male
helps with incubation and may sing from the nest.
Their song is a cheerful warble, similar to that of the Painted Bunting
. There are subtle
differences in song between eastern and western birds, at least
where the ranges meet in Alberta.
authorities split the eastern and western races of this species
into separate species:The Western Warbling Vireo,
V. swainsonii, includes V. g. swainsonii, which
breeds from southeastern Alaska and southwestern Northwest
Territories to the Sierra San Pedro Mártir, Baja
California, and V.
g. brewsteri, which breeds from southern Idaho, Wyoming, and
Montana to south-central Oaxaca.
These two subspecies winter in Mexico. The
swainsonii group also includes V. g. victoriae,
an isolated population breeding in the Sierra de la
Laguna, Baja California Sur, and migrating to unknown wintering
Eastern Warbling Vireo, V. gilvus, breeds
from central Alberta and northern Montana east and
south through most of the United States and parts of southern
Canada, outside the range of the previous group.
south of the Isthmus of Tehuantepec from south-central Chiapas to Nicaragua.
It completes its autumn molt on the
breeding grounds, while the swainsonii
group completes it
The Brown-capped Vireo
), resident in Central America and northern South America
, is sometimes considered
conspecific with the Warbling Vireo.
- Foster (2007)
- Gardali, Thomas and Grant Ballard. 2000. Warbling Vireo (Vireo gilvus), The Birds of
North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of
Ornithology; Retrieved from the Birds of North America Online
2009-06-22. Subscription required.
- Database entry includes justification for why this species is
of least concern
- (2007): The potential of fruiting trees to enhance converted
habitats for migrating birds in southern Mexico. Bird
Conservation International 17(1): 45-61.
- (2003): Birds of Venezuela. Christopher Helm, London.
- (1989): A guide to the birds of Costa Rica. Comistock,
Ithaca. ISBN 0-8014-9600-4